The correct answer is A. reeducation camps. This is because reeducation camps are camps to which people are forcibly taken while the others are practices of traditional Chinese medicine.
The circumference is the distance of the earth that is measured around the poles. Eratosthenes method of finding the circumference of a planet with the sun's rays cast a shadow on the equator a vertical stick of 2,500 km making an angle of 40° with the planet shows a distance of 40,075.017 km.
He also estimates that the meridian has a length of 252, 000 stadia. And described these techniques in his book measure of the earth.
